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LA-UR-05-7771
Tifft:.
SuLvrutteci to.
.. A ·~Los Alamos
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SURFACE EROSION MODELING FOR THE REPOSITORY. WASTE COVER AT LOS ALAMOS
1 NATIONAL LABORATORY TECHNICAL AREA 54. 1 MATERIAL DISPOSAL AREA G
Cathy J. Wilson Kelly J. Crowell LeonarcJ J. Lane
U.S. Department of Energy
.A.l;JrflO'c~ \ia1ic}ndi Ldb(natcry, an attrrrna11ve actkm;f~qJal opr:;"::rtunlt; ernp!c~·:ir:r ~~-:i un~:raF~d Ly ~hf~ Un1v8rsity Qi C::lht.·vnt~1 fur r~·tt.:· U.S (}t;~~:dnrHt;~nt LnPr;r~- tW=·JtH co.rtrr~ct V.J· T 40f:~~ENG<36 By uccupi·:jn(:•.~ th1~:J ;;trlc~Glt:. HH: uutAtsLt:•r r(H'X:Gn:zes tn2; the Oo·v~:t fi("PH11
.r•·<.·lin~-: C:l nr;nexciL:.~''lO- rt;y;dtv~lrt:i.: ~tCGf'tSE· tc pubhsh or ;·er~rzY'.ilJ>:-' th-::~ C'UbiL;!v1ed torrn th!s ·~;onlnt·,u1!CTl, ut tc fdk,w .:.::•H'h~·r:;· 1•> f::.}r
~~'1~~ .. ~.).S :.>:::pJrt:nt:~nt Ent~:HJ/ L,_-.<; Alarnus r ~.:uion;1~ Ldt>Y,Jtor·., .. - ::;u:;:..\~)<~rts l~~·:;~·tci<Jr:TC he,~·G~JrT ::rnt: : t---::.t<:l, ·~qc·r ~~ r<:r, 1 l. d:""i ,:·,~·:\U:.Ji!GH jyy,vc~vvr F1s::' L:·:Jh.'\'"'·;t.·d·\, tin~?~·.~·,. ,1 l'H·· r lutil!(>~tkJn 01 qlkJd:·i!P(: 1L:· l.\)1 !,.~.:..::rn •. ::;;;>::::s.
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Table of Contents
1 ,()
2" Development of SIBERIA Parameters for Material OISi>OSal G --· ........ ,. .. 2.: i Local Data ................................. ,... .. ................. , ..... . 2.1.2 2.1.3
Definition of a Steady-State landscape-Form:ng ........... ,.. .. . ............ ~! Estimation of Runoff and Eros1on. , ..................... , ........ ,. .... ... 9 Secliment Predictions., ............... "" ................. ,. ....... . " 12
"'; ~ ., "~,,. L i
Results........... ..... ..................................... . ....................................... , .......... .. D:scuss1on ancJ Qualifications ........................................................................................ .. 4,1
Data ............................................................... ,. .. ,. .......................... . Comparison of SIBERIA Results to Field-Collected DatEL ........................................... .
References ..................................................................................................................................... .
Figure 1 F1gure 2 F1gure 3
Figure 4 F1gure 5
F1gure 6 Figure 7
Figure 8
Figure 9
Figure 10
Aenal Photograph of Material Area G . . .. . .. ............................................... 2 Proposed Configuration of Cover for Material 01sposal Area G .... " ................................... 3 Sediment Concentration Data for Runoff Plots. Small VVatersheds. and Canada del Buey .................................................................................................................. 8 locations of 17 Hillslope Profiles in of f'v1atenal Disposal Area G ....................... 0 Phot.:)graphs Showing Expected RangE' in Canopy and Ground Site Closure ..................................................................... ., .. ,....................................... .. 'i4
Excess Runoff Values and Ranges for Soii-Type/Reiurn-Perioc ................. 15 Showing HE~,;l Profiles SiBERLA, Flow Paths Used dunng
Swnulated Annealing ........................................................................................................ 18 Correlation in Sediment between the HEM and SIBERIA Model for a Range of Slopes and Hi!lslope lengths (!ow-erosion scenano) ....................................... 19 Erosion and Deposition at MDA G for Moderate-Erosion Scenario (as predicted by SfBERIA model after I years) ................................................................................ 24 Eros1on and Deposition at MDA G for LovJ- and Hi1;Jh-Erosion Scenarios predicted
SiBERIA model after 1 years) .............................................................................. 25 and Depos1tion at Zone 4 for 11/oderate-Erosion Scenario pred1cted
StBERlt\ model after 1 years) .................................................................. ., ........ .. MDA. G Sediment-Source Areas and Sediment Catchments in Habitable
Bottoms .............................................................................. .
.. f
List of Tables .... -~-----
Table 1
Table 2 Table 3
Table 4 Table 5
Characteristics of Four Small Watersheds within !he Santa Rita Expenmentai Range near Tucson, Anzona {analog site) .................................................... 11
Summary of Ramfaii-Runoff Simulation Results for Hillslope Profiles at TA-54 ...... ... . 13
Summarizec Input and Output for the Three Erosion Scenarios Used in SIBERIA Mode! ................................................................................................................... 16
Summary of Sediment Delivery from MDA G to Canyon Catchments over 1 Years .... 29
Estlmated Sediment Yield for Meslta del Buey Sites from Events with 2- and
5-Year Return Periods ........................................................................................................ 34
i\I .. S\1 CRE.\\lS
\l llL:'I.l L:\'\;L \1D:\ }''>;{ ii\ '\ "1 .!\ WFPP
.\trbomc bs~.·r S\\ ath (
S\sh:ms rn
lli!lslupl' r J(\-;itlll \l(t(kl Los ALtrnos Nalldnal l \la!cnal Dispdf<ll Ar(:a '\J:tlit,nal Ckc:amc S .. ,\lmu·;plh.'rH.:
l~:dmil·:tl Arl';: \\ ah:r ! !\lSillll Pr,:d t<:lwn f'rnj~.·ct
Acknowledgements
for SiB E R !A par an tt.:lL'tTzatirnl was prov idvd h;, th~: aUl!wr of
"IB!J{l:\. (larry \Villg<HhL at the Sdmnl Pt Gvography, l.;mvcrsl!y uf L~vt!s. Sran at
tlh.' :\uckar Wa'>h: Operations at I .os 1\l;mw~ National l.ahoratory. pruvickd L'\pt.:rt~:->,· on
\!aTtTtal DispPc'a] Area G. pn•J'-'ct 1)\\:rs1ght and IughtlL::t! and fundtng support. R,1b Shum:m .. :t
t:r<.S (\~rptlraunn. pnn·1dcd guidance on pHlJCCt requirements. s1tc mforrnarion. and a h'YlcW
!he mudd r~.·sults. I\hrk Day and Garth Wd:1cr, at URS C\1rporatiotL d~.:vch1p1.:d the Cll\l't
tk~stgn datas;.·ts. Rttki Sheldon ;malyzed !hi..' runoff .md t.'l\l;;inn data l'Vh.:s!W dd . This
WOl'k wa:; Fnll<.kd thmttgh the l_: .S. [kpartmcnt of
~~-~--·------·····- ........................... ············--·--···-~~-... -·-·---·----···------MUA.; iV
1.0 Introduction
L:1hur:tlun) ~::> disppscd m pits C\ inh• the mcse~
.-\!\::1 I f\!U\l Ci nr Tcdnw .. :;ll :\r·~·:r (! Al ."~:.One' rc·qun-.:mcm for tl1l'
tlw r:~eii ·s d<hUrc. 'The LthoratPry 1:, rcquncd lu lkmonstr:!lc th:tl ilk: r'"'P''"!t,··t·\ em
bv ullY dtJs..:d. \\ ludt mduch:s sh,w:ing 1h:n wask \\i!! nflt he c\cav:lh:d
krm cro:;mn processes such :h rillm~ :md ng. 'I m\·ard the~! end .. ~urLILT L:n\~iH!l
mnck·!in~ \\as~{ to L>ilimatc the spuual dt'-;tnbu!tPB nf .;.kpth In waste~~~ \!D.:\ (i :t
1 .nil( I y:ars \lr cn.1'iwn :tml
\bh.·rial Disposal An:u (; JS ],1ca1cd on :1
~·ompk:-. l\}pographv aml a chalkngin~: lavuut nl·l,:ga~.·y w:ht.:· pus l·k·s~.· 111 tl1L· "
til<. !lh:sa and drainage knturcs i l L :\:; a result. tb ... · do;c;me C\>\:..T a
tz>pP~:raphy. :md th~.·
SlBLRJ:\ mmkl t \\il
-L:nn
bndscap~.· tPtL Lik...· \VCH-known hill:->lt.lpL·-ba-.L·d cw~inn motkls such as th'-· \\ ah:r Lr\IS!nn
Prediction Prnjc~..·t tWE!'P) (La!kn c1 aL, 199."J and K!NLR('JS <Smith ct a!., J<>9."L SIHL!ZL\
rr<:dtcb sediment tr:msptlri derived h·pm sha! and rill pru...:1.·s~es hll :t rang~.: S('tL
mnuff. \cgc·tation cmcr. and hil!slopc properties. L;nlikL· \\'EPP and Kl:\LJ{fh. '-:JHEHL\
prcdJc'b the SJXIIL.d di:::tributwn of zkfurnJ~lllun acmss ,·dn1ph:x. thr<:c-d!mcnsJonal
(1\Cr hundn:dc; tn lhnus:mds ,1f vcars. T'hi:;; includes the l1n\cnng tlh: mns on nr
miiilmg and
SclC:ntlsts at L \Hlrkcd \\ dh cover Jcslf:!:Il cngmccr:\ nt U R~ Corporalicm m an 1h:ratn , ..
proc(:s.s to de\ a closurl' co\ cr dvs11:~n l t· i.:2un.: 2 l. Tbc SlBFR!A mncklmg ;csulh
m this report dcnhmstrmc that the lin:.L optlmi~:cd th:sign meets pcr!(.lrn«mc,· c:r:kTLl
<l('l\lSS thv stlc :1 witk range potentia! snc <i!ld ,·!inmk~ ('Unditions that could occur o\.cr tlK
l.OOU-\'e:tr comptl:tnce pc·riod. Scrtion 2 ur :he principh:c. h .. :hmd Ilk'
SJBERL\ and !lw illi.:lhPds fnr ddining p;;r~tm~;,·krs and running the l!H~>.kL Th:..· n.>'>lllh ,1[
4
Fitture 2 Propo>>l:d Contlguration of ( ·(n er
for \lalt:da} Dispo!>al .\n·a G
2.0 Methods
TlK !ony-t.:nn l.TtblOil a:-.s~ssrn~nt al MDA Cl \\'as pcdi:mn~d using th~ SIBFHlA hmdscapc
evolution nwdd (\\'d lgmJSl' cl aL l 99 !:L I ()<JIb), 'This modd prcchcts skady-statc cnls;un and
M.·dinK·m transpur! :tcro~s a hmdsc:ap"· thal is T\,'pr~·,,,~med as de\ atiuns in a gxitkk·d digtta l
ekvat!1HI moch:l ( DUvl l Tlh: LH::'vl is ad1ustcd ('ach tlllh.' :->kp (l_vpicall,v l yean l\l ;lL'Cullt!l for
illl} ... ~hang.: m surfncl' elevation that lh.:currcd frum cruswn or tkpusition sinL'l' the bst umc step,
The gov~rmng equ:£1it>n t(lf lh~ SIBI'Rl:\ mndd ;s:
- B:!'" + D_S
Where
!) , the annual sediment flux through a gmlcdl (kg per mck-r width l
B .,. a Oltrticicnt that repn:scn!S all ll1ctors that moderate nmo!T-drh en crus inn Ill
the grid ceiL c:\ccpt slope and nmutr
A"' S¥1 the relationship ht't\\ecn contributing area Lli, slope fS1. and sediment y1dd
D. a diffusion cocfikicnt
S' the tciTain gradient tslope) (0 o}
Thus, Equation I mcludes sediment transport terms for both runoff-driven {advcctivc) pnH,'csscs
tB A"') and gravity-driven (diffusion) processes. The intensity of nnwfFdrivcn scdimcm
transport is given by B A"' S'. The coefficient B account~ fc1r a!! I~Ktors 1 e.g., vegetatiOn cover.
degree of soil disturlxmcc, and :>oil typt') that moderate runoff-driven erosion in ih•~ grid celL
cxcl'pt f(x slope and nmnf[ The S' value increases as the catdm11:nt an:a alwvc a l~l!l!
inl..:n.:as~s ( i.cq a catchrncnt area Jecding into a t!rtd Cl?ll equates ttl a greater ruJh)fl' vnlunJL~
f1nwing through tilL: grid cell) and as 1hc gradient the cell incn.:ascs. Tl11.: exp~.!nl'nts m :m~_l n
determine hi)\\' scdtmcnl yield depends on contributing area and slope fi)r a given site. and ~:an be
dctcrmin~.~d c-mpiw:ally (where data an: plentiful) or through an oplimizatwn pn~~~~ss usmb! uthcr
hi!lslopc-ha,;cJ wodcls, Diffusiv:: transport includes proc~.·sses such as rain;;plnsh tscdimcm
pan ides ejcchxl from !he surface by ramdmp Impacts). trcc-thmw ( ,.;,x!iment tumbled tknvnslopc
when the root ball of a falk·n tree :s cxpuscd at tbc sur!~1cc ). ~md animal burrow mounds. Tl11.·
thffusinn Cllc!Ticlclll iJ captur('s lhc intensity pf these gravity-driven scdml1.'!1l transport
Within tbc S!IH:JUA modcl, EquatiOn l represems scdimcnHr:mspon processes at al! scak;;, ln
addition. the ~cdiment yi .. :ld. Q,. when applied to ead1 time step over lung periods of time. is
t'qui\ah.:nt to the average annual scdirncnt that wr<tdd result fh11n large and small L'Vcnts ~111
r-..:tum pcrwds~ l:,qu,Htnn l ts soh~.·d rN ~_·v~.'f)' grltl 1.:dl in the SIBERIA mmkl thm1ain fur ~:ach
liflk'
th~·:-.,_' \ahn::s ~n \lU.\ 11. in thi-,
snd :md lH .. 'dLH:k
fli.IL': I> I
rctl l\
2.1 Development of SIBERIA Parameters for Material Disposal Area G
The tyrw.:ai apprt>ach fc,r
cdtbrak S!BLRL\ w Prh: or
SJB!:J{l:\ can h~.· par:tmch:nzcd
but 1!11.:-,c chHasch me r;~r,·. Tn cLTl\\.' th~.· rd:.uonsl!tp (\Jr nlm>ff~dnv~..~n lran-;pun 1/J .(
:.:mprricaJI;·. data llllhl C\iS! lor a r:mt:L' or hil and ~!'athCntS. ,\·, :1! a Llllt-'C' ol ;n-.;a
scak'> .. ·1 ihilblupc. -;ulm;t!crshccL and \\alcrsh .. ·dJ.
\iult;p!c raintltU.
(-.·xpcrimcmal rncasun:nh.'nt plot. hi!blopc. and .,,atcrshcd seal.:.·::;), bu! !hcsc dat;1 are
contimwLh o\cr time nnr the unif{mn quallt:v r~·quir~.~d for direct dch.TmHEtt!lm SIBLR!A
p:tram~..~t;:r values. They \\lTC, hu\\<.'Vcr. sutTicH .. '"H p;mnnctcrizing the rainLdl-nmtdt' mock!
lltS 1> ( Stt)nc c! nL 1 ()921 and lhc nm~.dT-sc·dimcn! y1cld HiHslopc Erns10n \11lLkl (HI \1 J ( Lmc ct
aL .:::ou 1 L Buth th~.: JRScJ mod:..::!
ad'>cetiv~.: transport !cnn in SIBERIA
.:\!though a quantitative path c.xtsts Ji.tr dcvc!opmg the \l' tcnn in S!BFRL\. dctcrrtl!lltrl~:
tlw it:nn.c dctcrminminn
candidate
that the ltlC<d
~~go. Ciiwn !h the
wnh
dr
·\ !Ina!
,;:;u..::h !hat tllC"
I kllll'-<llh ct aL 1! lJll':') h:1s '->if!Til irt:~mrl\ :hh :t:lc,·d
in ~~quilibrmm land-...capes. l 'nfnrtunatdy. \ksl!:r
the applicattun ni' these kchniquc:-. bccatts(' ,,11
may h~nc hcL:n cmpbccd rnpH.!ly :1lwu1 ]IIJHl(i \;.'ars
it' was conslt'<tmcd :1 nwh.:h bel\\ cvn S 1B U·U .\-
mapping c-\LS\1 t digital tupugraptm: maps. hn L'\ampk, 1!' a
\\ c!l~dct!n~:d !lncs al MD:\ (r k·d-in
J f' manv lh.'\\
ion I Dn an an1mal titnt:
r
for the dnruswn L~udflctcnt in
:tppcarcd :tcn.l"" tl1L.' :.:11c. then thL'
nature's h1ghly dynanuc nmotl and crustun raw.'>. !n natun;. lands-.:apc-l;lfllll!lg wnuiT ~-,cnt-.
1.lccm '>poradtcally. pt.:rhaps once every Hl. 20. or Ul\Hl YL'ar~. rather than C\cry year. ot
long-term datas~:rs ;,;huws that the cumulativL' ~,.:fleet il!' a li:w ··!argt .. nnHI!T ~,. .. ,-~~nh m ,:r th~·
monitoring periud b grcattr !han the cumulative L·ff..:rt llf the smalkr runo!T L'\'Cnts thai occur
every year. H~.:c:wsc SIBERIA is a stcady-stilk' mmL.:L the user must JL:tcnmth: !IlL' sue n-:turn
p-:ri11d l of a Llndscapc··l(lmling event that c:m h.: applil'd annually in tlK' mt•Jcl dom:1in w prc(li..·t
th~.· ~am~· long-h.·rm S\Xlimenl yidd that would be gl'n::ra!L•d through pcriPdic large 1.?\Cllb.
lhus. tht' parmnct~:rizaliun of the SIBERIA ~nodd for applicatinn at 'viDA(! n:qurn:d a
nmlti::;t~..•p appn.1ach. This approach, which is L'Xplamcd in more detail 111 th(~ fulluwmg ~(·ctiuns.
nH1S!stcd of six m;IJUI. steps:
l. (\tlh:ct, collate. and evaluate pnxipitauon. runuf[ and scdm1cnt~y1cld datu fnr t'vlt~slla
del Bw::y These data Wl'r(~ used to paramct.::rizc the rainfhll-ntml!T !SR9 modd the
nmnlf-crnston HEM. as wdl as lP test SIBIRI.·\ results.
Evaluat;;: lung-term runoff and scdimcnt-ytdd datasds from an ~malnJ:.: sl1c, the
semi and Santa Rita l::xpcrimcntal Rang-: {in A rvnna l. w cstimmc the r.::tum pcnod
landscape-forming events.
3. Develop rainl~tll-nmo!T rdationslnps ti:>r MDA G using the sdcctcd return period for
the landscape-forming evcms, a~ determined fl·om data collected a! th~.· Santa Rita
Experimental Range. Apply the ISR9 model using MDA G soil and \·egetation
properties and precipitation amounts for events \vith and 5-ycar return periods for
MDA (i ·nt\.' cxn:ss runoff vu!w:.·s predil.?tcd h_y ISR!J fix the 2- and 5-ycar cvcnts w~.:rc
used as input to th~.? HErvt
.:L Apply the H[J'v1 to pn:dict sediment yield fi:Jr hills!upes using a range nf slopes and
an.: as .
.:; Apply a simulat..::d multipanmh.:t-:r n::g:n:ssiun annealing technique fCwvvdl cl aL.
200-i) !o obtain values ror B. m, and 11 tha1 minnnizc the dilTcrcth.T bctwccn scdimcnt
y1dds predicted by HEM and SIBERIA rur thL· same set of test hillslopcs.
6. Estimate[). by matching SlBER.!A rc . .;ults w present-day topography.
2.1.1 Local Data Analysis A number l.lf rainf:ill. runoff. and ero~ion datascts have been colk·ctcd at LANL over the pa~t five
decades. S~.·v,:ra! lumH>.:rm pn.'c!pila!mn n:con:ls fix LANL (a\aibhk ~:t
'Jmp>iV\\?athcr ) were analy.11.~d in rclmiun to data po:;ted lzx :vies ita del m tb.·
Natiunal Oceanic & Atmospheric Admmistration 's Atlas 14 (NOAA. 2004) and wl'n: fuund to
h:t\L' 1\illl l ir<.'lJU;.'tk'Y \.'harartcnst;c:-. hn· J,·pwdu~.· lit\ and ,·;p.,,~ zfi :tlL.1h 1s. llL
"! li\.\ \tl~h 1-t r:~int:dl n daw \\ere ,·d lll tim ·'tilth, til('C,;_'
d:!\:1 \\ \.'ll'
ar~.: ;d:-;(1 :t numhL·r
durattllll ;md
l\A Atbs 14
\,j i \\)
!(Jr l~l! rulhlfTe\Tllls. Both dat<lSl'h W;.TL'
;md scdirncnl tP J fl knl' (_,:; ;JC !P t) llll.) ;md
mclm!cs
data. t..'\enb l(!r whtdl ramt:llL nmnlf. .mel s"·dmk·n~ valta:s :'.nd tnr
!han nnw \\ere mc!ud<..'tL
cn~nl by !he nmnff' \Olumt.' for rh: same C\T!lt. lnr the second dataset (rq1n:senting tht: SllLill
wa!crsht:ds :11 I A-."4 t!t~.~ Cafwda dd Blll') st:ninth L scdimL'tH L'tl!l('CntratiNt dar:1
\\\.'l'l' dcrn cd
during storm
iota! suspended
!he \ilh!t:'S ol Ill :llld
l1.Tlll ( Lquatmn l ). HtnvcYCL lh: \ arwt1on m <,tXim ICnl ron~.·...:ntr•tt 1\\n hl:l \\ ('<.'ll
:-;ubwatcrshcd;-, appears 10 he murc a t.<: pavmg, ~oil disturbatll.:c. and
drainage plpC> :1 di Hl.:rcnc<.: in w:~tt:rshcd ;tn:d or gradi~..~nt 5;_ In addition. !he C\ cnt tLl!<t ar..:·
not c·qwvaknt all si!cs Conseqw:ndy. il wa:. dl'krmm;;·d thai usmg thcsc data h'' dirvclly
paramcr<.;'!Ve the SIBER lA model was inappropri;!ic These data \VctL\ htm ,_·\·u. used :ts Otll'
means ,)f SlBLRlA mudd output.
................................ ------------7
c
g: ;s ;? 0 0
c Q
E
~ if 't
~ m @'
~~ In
"::)
-a f/)
n; -o
~ c. VJ :l f/)
<ii 0 ;.-
A
2 ,_,
.;, A
.. JA
:c ~
...
E~~'.!WS [227 [?~l·;,rt E2-~8 E247
fMDA cMDA L) cG·5J tG--61 fG-4 (C·2) !G·1 )
TA-51 Runoff Plots
MDA G small watersheds ~ ................................................... .
data set 1 data set 2
" bed1fncnt conccmration values iC31tula!ed from measured
t:~>mnt·BJ.'dmwnt vo!urnc divn:Jcd t>y event·wnoff volurne)
Seciirnen~ concentrations rneast,red t~smg EPA r-1nthod 16( 2
[ nurnbors md!~·.'atu rH..H~1t)or of New Mex~co swrveJ!Ianct; progrHrr~ qauqW<f.f staLtH1
(r nurnbsrs :ndtc,=1:h Ti\-~1. gauge number
Cai1ada del Buey
Figure 3 S1:dinu·nt Conn~ntration lhttu for Runoff Plots,
SmaU Watt•rsheds. und Canada del Buc:v
8
~lllt'll l'\.l\ ::1
t.hdll\. lh.:
ks \\en: L'll !bi:t
dciinm,e hi tt \ lllkl\ ~r]c, nf !h.:· mi !
~+'
2.1.2 Definition of a Steady-State Landscape-Forming Event
Jt l rn
;unpk·d r~:inLdL runofL and cn.,sun datas~.~t:..: ~'\L-..:1 t\li' LAN L or tll.:<trll~ :tl\:a~ •. A~
!h~· l•lll!!·h:'rm n.>e<ml ...;~·dim;;·nt· d:na from tfll.:: Santa l{ ltJ
r.\pcrimcmal J\.an~~.: m Southern .\rillma ,,a.~ anah/::d h' d~.·tcmtm~.· th;.· return !ur :t
·state Lmd...:c-:J!W· cvc:m tn a :-<'nunnd l'm nomu~.·nt Th~· ,1! the...;;'
tlw range nl'tlll.' ~ .. ·dmK·nt ~i .. :ld value~ frum ... ·\cnts wtth return P'-Tl1hb \•[::' and 5 y~.~ar" i.'Tahk I J
llns i~ 1n agrl>.'ml..'nl w1tll tilL' n:tum 1wrwd r.:clmrn~:n~.kd hy S!Bl·Rl:\'" author (Jf ~thr·nt 2 .. ~
y~.·ars. wluch wa:-- based on his ~malysis :1 tbtasct fi·mn furopc· l \\ !llgcKh('. 2U04 i
R:tthcr than ~.:hou-.v :1 smglc return pcnod Cor th..:: landscape-formi C\t.::nt. S!BFRL\ rtllb \\('r~'
jX.'rfom!L'd !1:n bnlll lh...: 2-and :'-year 1..'\t'llb. Till' assumption \\;1:-- 1\V(\ ~.~,,.·m:-
pr(>\ ide !uw :md hi~h estimates of s.:.·dim:.:m yi~.:ld u;,~..·r !he t tmh: Iranh.' nf lh(· mudt.:L
:md \\\1Uld :KTOU:H ti)r lht• UJKt:rtainty m U'i!llg tbta lh.lm ~m ;malug Slfl: 1\.1 cktemun:.: tl!v
landseapc-!umH!1,l.' (.'\Cnt Cor \lD/\
2.1.3 Estimation of Runoff and Erosion nH." IRS'> ml1ltration and runoJT model t Cl aL, 1 1N2 l \1. as u~cd !O 6timat1.' rurwft
Prcc1p1 !;!! llll1
\Vith and r.:·tmn periods. The lRS9 motkl \\:JS :1pplicd to th~· l7 hii!slnJh' n
in l 4 l;n !'>\ ,1 :'t1il typ..:s. ;-;:oh:ly !nntn and hqm ·nH..·se :·;oil typ~..", fwum! th~· ""il k'Xturc fpr the· \!D .. \ G CO\\.'r :JS gi\t..'n in the ~..·,n ... ·r dc-.agn spt.-cificalitlllS (Day ct al, !1 i::.
impnrtan! 1u nuk' ;lilhougll this ron:r i~; cumposvd uf' multipk h:·<.-rs wnh d1
sandy !u;tm. The lo;tm CO\T!' consi...:ts crmhcd tuff with a i, percent admi\tuh' or bcmumtc. and
the saud\ kmm ;.lSSllllll'S d Cll\ i.'r ur cmshcd tuff lW benhlnill~. Both CP\ ('C" induck:
th.· co\ cr. hut S<Jil hydraulk
. \\ hich m turn 1m.:n.:asvs 1hv ;mmum ol' mnt>tT tu croswn.
rock pnn tdcc.: pn JkYtion fwm sud:Kc erosion. /\::; cnvcr
surLhv. the amount c•f soil l'\lk,.;~·d t\> ;,·n,sion.
"'''"''''"'''''''''''''''' __ _ 9
0 150 300 Ill
Scale - "'.1\cltve nortlon of MDA G
- ~ HiHsJopt:1 profik~ w~~o-··n• sr:~il anc~
cover data v.H;rrt: coUectt::d
10
Figun•.; Location of 17 llillslopr Profiles in Vidnit~
of 1\Iatrrial Disposal Area G
rahle I Charactl•d'itks of Four Small WahTshe<h nithin the Santa Rita E:xperinu:nlal Range nt•:u· Tucson, \ritona (analo~ silt')
I Drainage I
Grazing Watershed ID Area (ha) System
I 4 DE •00 P\o~ation
6' I 3 1E"-00 Rotation "--~ ................ ......, ... ....._"'
7 I ut=~on I Yeur
B I 1 1E•OO I Year
':··f.'3F\Ofi;i,-dr;)tJ~!C {197t~: 1{i)1_l V{f:'!·~:
3tJnuaj .:t? ~ w ;,·>ff
~k vt~· 1f .·:!;:.;·
,11 ~< t' -::;:vi,.,_~~,.
I Vegetation I Type Soil Type I
8f1Ci Sasabe Clri1SS loarn
Diaspar !carny Grass sand
•••-.-·oP<"'"•-~-=·
I S2sabo sandy
loam
S2sabe I grass loam I fh13
f!:.:' 1f_! )'f>1t
,'f:h!7!:1fN7iiJt\U
rw;orf i:Jt'1U su:f!r;·r::;nt
Event Runoff a (mm) ~· Sed~~~~t~.l~'.?.J!~~-~L 2-Year I 5·Year J16-Year I 2-Year
1
5-Year Event Event Mean ° Event Event
9 5E•OO I 2.7E+01 I 17E•01 I 2 c:JE' I {1
1 3E+OO I '2E·U1 ....,.... .. .....,._..... __ ~--
l.6E101 3 9E 101 25E+G1 SE-Ui I 2JE +UU
21EYJ1 I 5 lE•01 I 3 OE •01 I l PE•(;(l I B OC+f/l j
uf
.· ...
Tlh: ll\draul!t.· pwpcrti~.·s 1JJ' the cnvcr mah:·nal dcll'nllinc tlli.· :~mount ·ll· runntf asc,ocuh:'d \\t!h
the 1wo bmlc,capl.'-formmg cvcnls A satur~t:~d hvdratlliL· conducll\tt;, \a!u~? of I 1 mm
( n -D l!l ) \\a~ assigned to the sandy !~Jam lll JL'CtlrdatK<.: with the \'~tluc pro\!Jcd b;, h:m ct
al \ !()!)_~·~ ii1r cru.shcd ndf A \~due uf6.:'i rnm l1r W.26 in. hr) was used l(n thl· loam :-oil: this i~.
hydraulic comh11.:1tvt!y \alucs wen.: used in tl1..: IRS'! modd to c:Jkulntc rwwll \alucs lor the r;tm
events \\ 1th ::-and 5-ycar return period:-.. As dis~.~us-;cd in more d.:tail in Scctiun th..:·
used for saturated hydraulic cnmlm:tivi!y an: high!;, unc1 . .-rtain.
Table 2 shuws the results or the lSR9 simu!cttimt:< includin~: m...:an nmoff vahtL'S and rant:cs for
each or the soi!-typt·hcturn-pcriud pairs (Lane. 200..f ). The pLTCcnl crmopy and ground cover vary
significamly among the I 7 hillslopc profiks: these cbta can he compared ttl 1!1~.· range pf cuvcr
values t':qJcctcd to c\ist <lflcr the closure of \1 DA (; ( F igmc 51. The c f!\::ct (if' C\t\'Cr vanatHm nn
runoff is cvicknt fhm1 !hl~ resul!s listed m Tabk 1 ·rhcsc rcsuh:-; also indicate that the mcrag~.·
nmnlT !i·om an annual bl!ds"·apc-forming event is likely to r:mgL· from about I lll l ::\ mm yr
10 031J In tJ.7l in yr) lkpcnding on the soil type. hillslnpc 1\)pngraphy. and cover propt'tlics ~H the
site.
2.1.4 Sediment Yield Predictions
The C\C\.~SS run orr ~.~stnnatcs calculated by the ISR lj rnodcl \\'CIT used as mput to the HEt'vl { Lan(.'
cl aL :2001) tn estimak hillslopc erosion r~sultin;c:: from the and 5-ycar runoff events ftx botb
soil types. The HEfvi is an erosion and scdimem transport mudd that analytically so!Ycs the
kinematic wave equation fbr sediment transport on a series of connected hiilslnpc scgrr1cnts 'The
modd cakulah:s the ~.:rosion or deposition in ~,~ach hi!L.;lopc segment as a fhnction of the sqn11L'nl
nmofC gradicm, ground cover. canopy covL'r and soil type. The HEM is wcil lesh:d and
calibrated to hundreds of rainf~tll simulator cxpcrimcnts perf(mncd for the WEPP model
calibration. A primary advantage of the HEJvt U\<?r the \VEPP and other hills!ope erosion models
is its case of usc. mduding tht: availabilny of an 1llllll1l' v~:rsion for rapid ~..·valuation of crosiz1n.
For this study. 1hc cmlmc vcrsiOil of IIE1'vl ( l.'SDA, 2002) was modified to run m a batch mmk to
generate s~.·dimcm yield values over a wide range 11f hillslopc lengths and gradients !or the
i.'omhmatic•ns of soil rypc and excess runoff shown in Figur-:: 6 and Table J. Three combinations
\V(TC sckctcd to n:prcscn! low-. medium-. and high-erosion scenarios at l'v1DA C:i: these arc
dcscrib~~d in nwrc detail in S(·c!ion 2.3. In hrid: the low-erosion sccnariD assun1cd that the
closure UWL.'J' \\(IS COJnflOS;.~d Of sandy loanL the ground and c;mopy COVer \\TrL' high, and tb;:
runotfc\cnt had :m associated value nf2.6 mm (0.! nL). The moderate-erosion scenario assumed
a sandy loam soiL muck·ratc eu\ cr conditions. and a runoff event of 7 mm ! 0.2S in.). The lligh
eroswn ..;ccJurJ(l assumed a loam ~H•iL !ow gr..:amd and canopy cover, and a rutll1fT even: \tf
12.4 mm tOAllnL.L
Tnhlt 2 Summary of Ruinfall-Rmwff Simulation Re..,tilh for Hilhilopt· Pmfilt•" at T.\-5-4
Hillslope Profile 10
E.\-lf;; NE
E\~ 1 SSE
EX-JS SE
E\-5S S
EX-6N NE
EX-?N ~JE
East-1E SE
Mean-- SD
Amount of Cover(%) a
Canopy Ground
~ .fE+O': 4.GE+CI
4.1 E+OI
BOE+OC
1.5E+01 4 4E+01
12E•01
1.7E"'0\
3 2E•01 6 1E+01
7.DE-J1 5 OE-01
2.0E+D1
Estimated Runoff (mm) ~>
2-Year. 6-Hour Storm I 5-Year. 6-Hour Storm
Sandy Loamc s 1 1E ·JO
2.4E+;)O 6.7E+OO 71E<O
5E+00 9.2£-G(;
7.0E·OC:
2 6E+OC
7 OE-Ui 4 OE-01 2.0£.0'
7 CIE-01
4.5E+OO 9.7E+OO
~
~ ~
v,
:::.. ~
'-E
::
,:; :;;:,
,...~
-;..:...;
14
-r':J <
""',
~ ~
'~
.... ;:;
~
:::: ;..
:.; 0 :.;
"0
;.-., ~ §-
c:: ::'.:!
::I;
"' ,-v
~-=
o::> tt;;
•r. t
:;,; - ;... ""=
Ct ,- ... , -- ;; -=
=
1fr
~: 0
:::) 1() ~
(/) (/) (j) (.) >:; w
5
+
0
············-----' ·,> .)~ ',· ,' , .. • ,, ~: ;.
!uarn/5-y-r
~· " Mean excess runoff computed usmg da:il from al! profiles
= Vanali0'1s 1n excess runoff cJuv to and cover diHen:nc>:s at
Figure 6 i\lt:an Exn:ss Runoff Values uml Ranges
tor Soii-Typt•iH<•turn-Pt•riod Pnirs
T:thlt .' Summarizt·d Input and Output for the Thn·t· Ero~ion Sn~nariw. U~t·d in SHU~RIA l\lodcl
Model Parameters
pcnod i'1 years)
Excess Runoff \TirF)
SIBERIA Model Sedtfncnl Yield i T/h;;lyr)
100 vears
500 years
1000 years I
Erosion Scenarios over 1 ,000· Year Period
low I Moderate High
Loam LODH1
70 I 70 30 •. 7!! JU 3D
5
7
5.0E-Q·l I UE+OCl
~.OE-01 I 1 1E+O[;
.4\JE-()1 I ' OE•OIJ
Th~· llL\l n:il' \\C:lc 'lnncd f,l; th(· 1\lw-_ ill"dnat~.-. ;md '"lC!ll p~tLtnKk'r -<l:-: >hil\\'1
ttl -~ Jill i'tc wl hd l:-;ltlpcs. lhv lH \h'r~_: •.:nnsi ruc:kd lf• r~·pr~·:-.c!l!
]-- lk· hdi--:J11p(· S('d!l11~'lli
<:r,,>l•,\lll "l't<.: then compar-..:d to
ti' rmd lhc !WU
U!l tik
ll\llll run" { hm. mdck·r:lll'. :1n'"~
'<.: "L'h ut' S!Bl.RI\ run> !ld\\.
2.1.5 Optimization of SIBERIA Advective Transport Parameters the SIB ER L\ parameter v;dues ror the ad\CC[ i \'(' transport tern I fJ s· ~ hjtLHIOfl [I \\ ·,'!\'
\Pre~> ~.·t nl.. I 'Nfq 'lik' ck\ L·lop~·d thing an npt process :-;imuhncd mmcal
prtll?CSS n.:quil\.'S !he tt;>LT hl
tilL' nght par:lllll'kr
a set e>l \'~!lues and an l:qnatit!JI thaL wl!L'll snh .. :J wn!l
w!l! match tlJL· targ•:l \':tlw .. •s. ln thh an::lysh. the llL\·1 ·<dmJell!
ytckb; lrom th~..· anilicLil hiib!op:.::s :-;ho\Ht m hgmc 7 \v~.·n: the targd valul'> and 1 1 \\J,
t!Jv C•.]U~lll\>11 \lf imcrcsl. f!Jc simulmcc!<mtk'almf:_' aigoritlm1 Wi\S used lO lllllllOllZC thV d1 cnc;.:
b,__·t\h'<.:n the !H::f\1-p!-.;:di,:tL~d target yidds the S!Bl:RL'\ .~cdiment ytdds for sd-; l( m.
n and !J. \:due:- optimal 3\.'t or nz. and n values shm\s a mimmal difl'cr~.~ncc k:t\\\,'cn! !F\1
f--or a gtven fHd the HEM prmid..::s iut:Jl SL'dim~.·nt flu:-; (kg), rww!T umc lm · ). mc:nt
sediment concentration l''uL tmd nlh::r-n!l :md rill dctachnll'nt and dq>(lSllHm rate~ f nu una
pcr-mdcr-\V!dth bas;s. ·rht.: SlBERl!\ moe!..:! prw:1des ou!pll!~ aHowmg an cqtmakut nl~b;,
flux tn he calculated alon1,' a identical to tlh.~ !IE?v! prunlcs. Par:unckrs !!. m. n. :ukl D ..
CmtCl11lll usc:d w~b tlh..' ;;um nl· th(• sqturcd dif!(:rl'nu::-., hcnn.'en the nd ..;(:dmwnl ilu\c'-. that \\l'L:
cakul~!k'd bv mo nmdds along t!Ji.' artlllrl<il planar hillslupcs. The simulatcd-annc<tling
•ns J1·om lht.' hill.,dopc:-. ,;[J(l\\'!1 m F1gmc 7. Lengths ran)!~.:d (rum .in 1o
1 :;o m r<>s tu -DO Ct \ and \V('rc sarnpkd L'\ cry ntc:cr. \\ lu L.: rangcd f'n.nn 2 w l {• fh'!L'Cnt
at 2 PL'I'CCnl Jrl!(T\:ds rhi:-> _nddcd XOR hill:-;lnpc c·ascs {! 0 l ;;!ope times ;;; gr~tdicnh) llh.'
upp-.T k·ngth \\Us tt\ aYuid edge cff\:cts at thc·lulbk1p'-· prniik (·nd.;. The slh.lrk'Sl ln
kn~th wa~' dJ<.ISCll tP I mail L'fkd~; •. .luc tP difil.·rciK('-, m ts c::ku!at-xl
mJZ;::• Jm 24m
- .. +
=Base leve!
" Eteva!10n above base level
"'SIBERIA flmv paths used 1n s1rnuiated annealing process
Fi~Urt.' 7 Artificial Surface Shmving I-IE'Vl Profiles and SIBERIA
Flow Paths Used during Simulatt:d Annealing
)(
~
c:: (l)
E Q <.h
Q) c m ::; c:: :::: <
4
2
Fi!,!un· S C:orrdatinn in Sediment Yidd IH·hn:t·n tlu· HEM and SIBERIA 1\lodel for
a Range of Slopes and Hillslopl· Lengths (low-ero•don scenario)
2. 1.6 Estimation of the Diffusion Coefficient
W1thin tlk' SHH RL\ llldtkl. ditrusillll JS added 111 :td\t:ci!Vc tr:msrort as the pt nl th-.·
dtiltl''lon cp;;:·[lincnt. f) and the hilblupc grad1cn1. S .\ch~:ctivc and diflits!,~..· arc
thnught tn be largdy in bahlncc tn the mHJJ<itllrbcd pPrti<JI1'< \tcsiu dl'l But.'\ !lK·n: dL-'
nn ''dl-ck:\dl)pi.'<L d:.:·cp ~ull or deep collm·ial fill~ in ll..:adwakr n:gions un the nk·.~~L \ ~llues
gn en !'(It' [) in litcra!utt:' r;mg,• 0\'Cf ~L'\ era! ordch nC l1 oagnitudc; 11 W<!S !lOt possibk• lu sdcct
a 1m:~mmglul \ alt~<.: among these for the :-~pccd!c :me conditiOth. Although t!h: -;Jmubc .. :d
:mnealing pruccdurc found f) V<llucs fur llll' t!Ut'l' ;..·r,_)sion .:;ccnarins. these values do no1
the full r:mgc diffusion processes rcpn.:s~.·nhx; Sf !:\ b~tatts(' tiH.: HE:Vi nH:!uJc.:; \1!11~
that comp1 \l1C!l! of di ffusit>n c;msed by minspla::h. ! n J'l:alit~. hmtic and other processes nmtribmc
sJgnific:mtly w drllusion in the landscape over long ttilk' scaks anJ lnti:>t be Ctmstckrcd
To cktcrmmc a sitc-sJH.:dfic value. SIBLRL·\ nms were tnadc using a nmg<.: Jl \~dues. ·rlh'
resulting topography was \'isually inspected Jnd compared to current wpngraphy as rcprc'<cnt~:d
by the DEM Lh::rived frum ALSM. The compariwn !\l~,.:used on gullies and hol if SIBERIA
pr.;da:tcd the development of deep eolludal fill> in the holhnvs. it \Vas assum.:d that ditfusi,m
\Vas too high relative to advcctivc processes Wuvialtranspor!l. '>vhcrcas if SIBERIA pn.:·dit~h:d
c.\cessivc gullying. dim1sion \Vas consi,kn:d too knv rdmivc h• advcctiH' pwccsscs. For tills
analysis. D: values of LO HY"1. 0.0025, and 0.005 were used as input w the moderatc-croston
s\."enario to assess th;: impact of diffusion on the Lmdsc1pc over l JlOO years of ;..TtlS!UlL
'The low D. value of l .0 1 (r4 led to the dcvelopnlcnt of a highly dissech::d gully network. which
currcntl.y nul exist a! TA-54. As a n:sult, this value was rejected as being lol' lov; fen th.:
current modeL The middle value of tU)(!]) r.:sulu::cl in a landscape with rnon: t!K·
(~hamctcristics of the L'Urrent landscape. wherca:-, the high D~ ·;aluc resulted in a land:c;cape that
looked mudl more romulcd than the current landscape. Because !he results <JSsoci:llcd wnh the
rnidd.k vahtt:' ;..cem .. ,d to b..:st n.:pr..:scnt cotHJttil•lt:' at \IDA G. and because rw bdKr uH:tlwd rur
estimating the f)_ \\as available .. the value of 0.\!0.2:" was ,;.·hoscn as the mockr;nc-crosion n valw.: and the bcsl valw.: for tv1D/\ G.
A n_. \ alue or (J.OO l was dwscn for the iow-crnsiun :-.ccnario. This value was sclcc!l'd hccatbL' a
ltl\\ dilTusi(lJ1 rate coupled with a low advcctivc-crosion rate should yield the correct b<!lancc
between tiK: rwo processes and result in a tnndscapl~ that looks somewhat similar to thL: nrm:nt
landscape: this diffusion rate would also result in sluwcr overall cn•sion than the nwdcratc- and
lllgh-eroston sn:nari(\s. Similarly, a De \aluc ot' n 005 \Vas used 111 comhimnion wJth a l11gb
croswn rah:: for the higrh:rosion scenario. A more rigorous test of !hl: effect of' f) nn land:-h:;qx~
fnrm is dcsirahh:. but c\pcns m the field of lantbeapc evolution mw.iding: suggcst that this
approad1 \\as r~·asonahlc gi,·~:n the state of the scii:ncc (Dietrich. 2004: \\'illi-!POsc. 2004: Bras.
2004 J.
2.2 SIBERIA Model Domain Configuration
!. ~0110 .\L:-,\1 c.,k . .=oo2) the f}l\Jp~~~L:d CP\.t.'l' "~h .. ~\ ,Jl!i.Ht'
dl'llLllll !\VP ·rh;.;- \ .. :r L:- .._·nlnpd:~c~-~
..:·n\·cr n:Jt~.~rial pn1jwscd
lll!f ;Ju~:m~.·n!l..·d wnh b,·ntcmitc :mel :mpd:u
•.'\ ;d t2005\ iS
P\ crlmn \\lib a
'c~~.·t:tll\lil dum!."' the :1ctivc msti!lltJoJwl conn'!
,:,,, cr ::md rcdu~.·~.: ,~roswn. The s~.·nmd l:l\ n 1~ t.:PlllP•'s-.·d
al~'' tnmsttlt>n
it dur:~ ~KI.';\Ltllt th._· sp:ll ·
domain. !n natUJ\.', the nne
cxh:llt or;) materialtyp~.· that is
h,·drnd. Tu ~imubk· thi-; ,<~tuatiOtL S!BLRL\ ''as nm in a Hstart-slop-star(' m<.ll.h:.
w;tS stopp~·d alt~..T 1.'\ c-rv 20 :·cars <Jt" simuL1kd time and cad1 ,:d] was ched.,(·d to
clc\aUon had dropp~,_·d he low the surfaL·e. (db tha! had n.::lched bcdrnck W(:!('
as such so thai cwsion wnu!d pnKl'Cll at a sltn' cr riltc. :md the model was
mnd,:l
'if its
The disposal ln:. w~ts divided into two mud-.· I r,:gmns: !he dct.i h' p<miPn of r>\'J ( l the
Zone -+ ('Xpansion ar..:a (Figure l Th'-' samc Sl HE RlA paranKtt:r values ti·lr c·nbtnn \\cr .. · w;cd
f(Jr hoth areas: hmvc\ cr. thL· en\ l'r ~tzc and depth and pit conr bet\\C~;'n the !wo sites
torts are dufcn:JH
2.3 Model Scenarios
\1 D A G a lkr 1. ono vcars
was tn estimate rh~-· spatial distribution nr depth to w;t';t-.· ;tt
and s•.:dmh:·nt transport Any such estim:ncs arc unct:rtam
du..: t<J potcnti;d Vdriations m clintall'. sod prnpl"nics. CYP!ulitln the vcgct;ttwn ;,.lrtldUIT, and
nthcr t::KttlfS m ..:r thi.· l.tlflfl-ycar time ir<Hne. T hdp constrain the uneLTWmty. t luc~.~ S>.'l'nanu::.
were LIL'\ eloped that ;m: h' rc-;ul! m lo\>.. mmkratc. and high rates of crusH on at tlL' site
Lach of ot!lcnmcs ts plau:;ibk on !he !ung~tcrm cruskm ratt.·s l'i:purh.'d m
the !itcu\urc ( ct aL .:::oo l) and CU!T('nt obs~,'r\':llions. The paran1ctcr ucs l\\i
\ cgL·tatlon. r;unblL ruunfl cros1on. and scdink'n:-ytdd
prnpcni~.·s
IP!h pro\ '-'!l g !ll1.'Cf.'> ( f:b ~ ('i
I
Th(' km-cnh!Pll :-;ccnariu us:;umc:-. that rll.: '>oil will ltlt\c the cro:'ion and ntrhdl propcnll':-, ~~
sandy !o:m1 tcru:-lh.'d tun cmd g.mvcl w rw admL\turct wllh high mfdlrati\111 cap:k· . a
l!ud; \,:p_dalJon c,l\'L'r nl natlVL' tc;r-H)py t'O\cr ,~r 70 percent grnund nwc t1l.
70 p~.-'ll'Cnll. and an annual (h:S!f'!l runoff nt' 2.h mm { 1.{1 tn. l. The mnlkra!l.·-cw~:;t.m sc:.:narw
rdatncly undhmrhed cPndiuons that exist m Zone ~1 at TA-:'\4 and at thL· ca~;rcm
dd BLII.',\ 1 i.e .. canopy cmcr of 30 pen:cnc gruund cu\cr pf' 7U percent] The mmual
runoff !iH· the mmkrat~.· scenario is 7.0 mm tll.2?' m.L The l~tg,h-crtl:-.ion se.:narm as~un1cs ;1 !,,lml
soil\ ,:ruslll·J tuff and j!W\'d mixed with tk'lHunitc L a sparse \,;:gelation cover wi!hm tlh.' of
c'Ollliitwns !(nmd on :VIes ita dd Buc;, ( t.c" c;mopy cuv~:r uf 30 p~:rc.:nL gwuml C~.l\ cr ol
JO perc em). and dn annual design rtl!Ht!T of 12 mm WAX m. L Th..:se Sl:cnarw paran1ctcrs an.:
sumnmn/;.;d in Tabk 3.
3.0 Results
cof 'rdmat ion
an
the· nwcr
nn izcd
:tt \ RS ( PrpuLtlWL.
1ha1 \\as "'·"f''-'L'kd w s~ttrc;i\ ti;;.:
slW\\ n in '} l 0 and l l. 'The;;.: 1 .nun y~.-;1r~. .·\u Pr:m::<: ::r~·cn <.1\.:r p11rtt•nt·' ,)r the
c'<.llor scak·
depth tP waste \[dttl's 111 e.\ccs . .z uf m (h.::2 ft). \vh~.·rcas 1brk or:.mgc that 1
appmaLl1111~ a ur nnly 1 m (:; .. ~ fl). Tlk' blue red col•;.r scak on tllCSt'
cumubti\c
the d;sposal units at \lD.\ (i I.Oml vcar~ aikr liL·tl
Awa\ !!un1 the tTusmn did dcpositwn ar~.·
seen w ;n cas rnark cd
uf the nh:s~L .Figures 0:1 und l Oh shnw :·dllll [ar r,:sults fin· the low- and hlhdl-l>\•S!\>ll
,11 \!D-\ G. While greater crosmn is nutcd m sonk· portitHh lit\ u1
erosion ~.·,mdnion:-.. a minirnum m (5.7 ft1 ,:uvcl appc;m, lo C\t;>l U\::r mosL ifnut :dL
tll. the disl)'l::>al umH, Figure ! l shows the depth-to-waste n:sults for !he mndcratt>Cr'P:ihlll
sCC'Jtarw at th~.· Znnc 4 C.\pmlsiPn at\.\L H.csults fi·om all thn:c scenarios shO\\ thal a mmmmnt \)(
l. 7':' m j :'7 tl) tlf >.'tWCI' C\ IStS acnhc. the S!IC at lh~: the l.\!00-vcar Sl mublttl!l
\
SIBERlA at ;dl PUtnlc.
\ L'ars :<>r !he
ln nddilhllL tmlv
\'<lftlL'.S from 
an 1i:)0 rn
Scale
Site conditiom;_" Canopy cover = 30% Ground cover "' 7()~\o Soil"' Sandy Loam Runoff evEmt "~ 5 years (7 mm)
Diffusion coefficient = 2 5 x
Dnpih 1o wasltl (m) ;Jf!er I "000 years
Fioun: 9 "' Erosion and Deposition at :VIDA G for 1\'lodt>ratc-Erosion Scenario
(as rmedictrd by SIBERIA modd after 1.000 yc•u·,)
24
i'tt:mc !Oa. L (>\\ ~cro~ton :-,ccn•tnc> i 7V"" nmnpy cO\ ,;r. 'i(J'';, ground cover. Jo.m1 soiL nmnll
hb;urt· l Uh.
ll u)ver. ''andy kum "uiL nmcff
('\t:n1 (!.2 mm(. and c!Jffthll!llcudfn:tent of:.:; s l
Figun: I II Erosion and Orposition at \H)}\ G for Low- and High-Erosion Scc·narios
las pn-dkti.>d hy SIBEHL\ uftt:r LIWO \tarq
·.-,, :... . ,·. /, .:.
Lkpth lO Wtb!C trni alter 1 J)DO years
Figun· 1 J
Erosion and Deposition at Zone 4 for 1\'loderate-Erosion Scenario (as predicted by SIBERIA model aftt•r 1.000 year'i)
26
the or \•ksiLI dd Bu.::v :md the \\atcr drop dL\~~ram (k\ '·
\\ 1:l1 th~.· co\\.~r dc~i&'u elTon ( D;~: ,·taL. 2005. hgmc 4 J.
catchment Jll the canyon. ln !ll:Hl!KT the
pntcnl wdl <~S !he t)ipc and conccntntwn pf t!k· ,·un1aminak~d
sediment deli\cn:.J H1 1llc canytl!l can tracked through lime. Table 4 summarizc~ till..' ddiHT\
o! the catdmlcllls show11 n1
Atthuugh t!w han· .Sh1n:d m; <: runctwn of ttm<.· and disposal urut. L1bh: 4 >huws til~.·
!i1Lll scdnncnl \tcld imu each catdnnent for the lJJOO-ycar hank~. lor C\<tmplc. mer the
l .!HlO-: . ..:ar penud. P:tjanw Canyun catchment PC.2 was proj .. xtcd to n:cci vc ?-;. 99:" ·r 1 t.J. q 15 t J of
.;,x!imcnt tlTm1 nncontaminmc:d purtions of \H),\ G am! /(11' ·1 ( S4-+ 1 l from pihti'fc~.·tL·d an.:;t:'-.
thus. !Jli-a!fcctcd sediment Js X pcn::cnl or the ll\tal scchmcnt delivered from the rncsa t\1 P( :::
:\ote tha1 the dr:nnag(· bnundarics may change through llmc. For C';<lmplc. b"·twccn 0 and l 00 y.:.·ars the em cr o\·cr a given pi! may -.pill sdiment 1\l PC2. bu! from l 00 hl 200 vcms. some ()!' of the CO\('!' \>\C'r !hnl pit may spill imo :;nothcr urainagc. and thcrcf~HC be
;mother catclmH.:nt. shdts m scdim(~nt >lckl ar~.· alsp tracked.
28
!"~
J:.
~ -~ ::
.~-= ;;.;. -, ---s ...
·1 ablt: 4
Smnmar.' of Sediment Iklh rr~ from MDA G Hl Can~ on Catchment-. HH'r LOtiO) car'
Canyon Catchment Mass of Sediment Delivered (Tl
Pit-Affected Sediment as Number Clean Sediment
l Pit-Affected Sediment %of Total Sediment i
PCfi 5.644 76 -
'(1 '59.3? 5tll ;
°C2 8,995 i't)(i ;
::JC' 8.823 1 ,25; L! --··· ·--
°C4 5AC:S 1.-\ClCJ ·-~; -PC5 6.549 1,340
::tCS 5A35 :78 0
CdB: 3£~.93(~' J-182 3 .. Cd62 1 ODS 153 3
LJ!chmerrr r:atclrn1ert
····-·---····---·- --c-··-···· .. --··-········---' <, , • ;..._ '.' : '.' >', .~·, • ; .:.. >-' " ~'
4.0 Discussion and Qualifications
Th'-' S!BFRl:\ simulation:-; rcpr~.·sent a srgmfic:mt stq\ forward H1 C\n
a:-. a!hm the fccdb;n:k between cro;,wn nnd th~.· shape of the n::pu:-.tlnn etl\l·r I<l ~·\plon:d
O\'Cr d h1ght;. rnnlp]c\. topography, ·rhis \VPrk a robust application SllJl:J{l,\ and
tlfllinn tilr asscssmg tl1L· pcr!ormancc of a co,·~.·r to hmg-tcrm ('roswn \:<..'\
Stgm!\,::mt lllh.~Crtainty 1!1 the predictions. llH: . ..:~_· utn:crtamties ;m: the result of bPth n1t•dd
slrm:ture. as in S;:ction 4.1. and lack of adt.:quall' data fur modd p:lr~mk'lC\'1/~tti,m. a:-.
dtscnsscd tn S~.·ction "' Lvt·n with these unccr!annt,:s. hnwt.:h:L th~..· Sl BLR l A sed1mcn1-;. tdd
pn:dtclwns wen: in !inc wtth h.lttg-tcrm Ynlucs l ned m tlic literature a;, \H'li ;ts \\ ith tbt;t from
.Vkstt~t dd Btl\.'\'. as disl'uss~.·d m S..:ction
4.1 Model Limitations
Th .. ~ S!BLRL\ modd wa:;; chns~.:n hecaust: it wus !he only bndscapc t'VolutJOn mndd that had
been applkd to and validated l{n· critical em iwnmcntal pruhh:m,; con,;traincd by l'L'gu;at inrh
such a!'> mtlk' reclamation and tailing pile n:mcdia!JO!L The modd vcrswn used :-:wdy,
lumL'Ver, had fom potcntbl dr~nvhaeks. First 11 d1d not automatically modify· mah:nal pwpcrtics
in cell.-. when erosion cut into a nc'k lay-.·r. Secord. the sedin~t.:nt·transporl-capacl!y ~.·qualt\'fl may
cause spunous deposition to occur when there was a change in material type along a l1uw palb
hum a nwh:rial with higher transport capacity \ ~?.g . the coven tn one \\ nh km er transpon
capacity {~.;,'.g .. bedwd) In addition. the modd do~.·s nol allnw panich: trackmg or scdnn'-'nt
pa.:·kct tracking through the landscape. hence it is impossihk h• dcknninc if the stedim...:nt that
;;:rndccl from the cover over a given pit was tr:1ppcd pcrmancntl)' in the rock armor. t~r
made its way hl the stream bottom. Third. it is likdy that a dynamic climatl' wiH gnl' a ddl(·rem
result than the steady-state climate the user is furc.:J tP ~tdopt by the SIHERL\ nw,k\. ,\nd
fumth. the mGdd d1d not tncluck an cxpl cllff-r-:·trc:n algorithm. /\ nc\\ version of SlBI.·Rl/\
is currently being tested that addresses all but the fourth of these issues.
[ach or thl.' model limitations noted above introdw.:c~ uncertainty in the modd results. l'he f<~~.~t
that the \crswn of SIBERIA uso.:d for this swdy did not autumalically update materwl propcnk:s
as en>siun progressed to a new layer was ilot a maJ<lf pwblcn1 sin-.:c t!Hs swd;.· mmkkd only !Wt'
mi!lenals. a homogen>.:mb cover material and hcdmd.; hL'll so. an effort was made to minimi7c
th.:.· dlcct that this limitatwn had on mnddmg n:sults. Dmmg the smmlarions performed l(!I tlus
stud;.. the nH ld;:l was manually stopped every 10 y~.:ars to cktcnmne if the ammmi
illc rhang.c m de\ atwn in a gl\ en gnd cell had cw::-ed the eel l tn mor~.· t'elow th;: \.:P\ ~.·r layer
bnundarv l f i1 hacL the cdl type was changl.·d from to ·'bedrock .. ami th'-· model was
n:~tarkd. !k·causc there was no wav uf knnn·iag when the hPtmdan bet\\ ccn the C\l\ ;.·r and
b"'Lh\l,.'f- J"hl h.';..'!l !,';l~·h'-•d
d•:\ <!1~<.'11 Pl. rlJ,·,
\ 1llU1\' di
Th;:, :lpf'l\\J;..'h !\ !lOI c'\fh.:~.kd 1\> t!llt\>cltk•.· Jrlltc !. ~Tllll
r;tk':< nf c'nl~;,q; \\ 11Lm tiL.' h~.·dt!.>cL :lie' ,;mall.
h11lh Cl\h!Oll :111d
ilk' lhl' \ll !lit:
<llllOUllt td \.'l
'll\
lc·d c•Ui \1 1'
l\pc ·'bt.::dnJcl.". h~_·;,;aw.~.· <'f tk: 1\ll k ;mnvt. :hh
of th.: ~.·u\ ;..'!'. l. nd ... ·r n;Hur;d ~:und!tluils. -,,·,!tm,·nt
from a nmfl' ,:rt•dtblc ;n<Ca \\ntdd .-;uy m su:-.p~..·nsiPfl .md !t<t\ ei
lwdtYlt:k :H\.';1. ln t!ll' nwd:::L tf the: l\\P l:;.:JJ-, b:hL' \ih Si\llil'
:md the s;mt~:
<..'\\\ LT cell <lllcl
stgrnfic:mt[y. fhis J<.:~ulh
~.::.m~co. thl' '>cdinll'lll tr :tnspon \ ln
at thl· tran;.;rt!Pn he!\\ ~.:,:n tllv cell, l.'oukl
p{hc a suppn.'S"-1.:,; ,;ro:..:wn ;H the
pwp<b,·d
s~.:dm1ent H·
a-;~igncd a ntn~·rial type
h'• th~· a~.::ual
other :L'>pc·~.·t td the
;.dhm p:midc
nt· tl11.· l'{l\ ,:r
"b~,.·dnlck." the mu(k·l in tht:; ~mution 1> lt\
PCdH. at A-1 Do\ T!m:o.. !h..:: mudcl l!mir:nwn nnlL'<.I
is that
will rcmam trapped in th;.: rnd: arnhH nr migrah: l1' ::
.\ppli,·atam of the lh:w \ ersinn c•f SHH·:RJA. l\hich
U\.it
Tlh' third
thth mcr-..::hl.'
bndscilfh.~ 1W1..'r time I! "' ould abo
th:tt Sl
..:tubh: k·
~,·pntuninan::.; \nl!
\ v the 1ssu;.:· uf SL:dtmL'Ill dn>ppnl,~
i.'._•tls
cy,•nt to
\'l' ,:n•sll•ll. i, l' l\l h:tn: a "lh~mfkanl Jnlfl<tl'\ on th~.· pr~.·divtt.:d ct~n:r in
natur,.·. !lt:Ul\ :~hnm:- ~·.t· di!"krc:nt dm~Hlt'lb and iniLtt:-.t!i ... ·> clt.'dn n single.· _y,·ar; ()\ er d
annuai rcrnanl:' !lH.: san11.·. r:nn m:l\ t.'Onk: m
rnnJI.' <.:wsion pc:r cvcHL In smmlutinn
fratllc' and the L'\Tnl r..:prcscnting ;J morl lll!ltkra!C cl:matL' OVLT th;tt :-.anK p .. :nod The
~_:bui,;l' nf tlll' "' and !and"capc-fnrming .·v..:l11' w;t:-. h;hLcd <lll d;l\a fn•m !he Sanu Rita
L \fkTtmcnt:t WatLT,;hcd m StHllhcm ts supporh:d :;,_·-, !l•r a~
diverse as Australia and England (\Vil!guns~.· ;md Riky. 1991\: \Vi!lgo(>c\L' ct aL ]'l(J
. the impacts
prnhahly be Ci.lflSidcn.:d m gn:at.:r d,·taiL new versiun of SIB! Rlr\
l'PllSldCr:lllll!l of an ,'VL'lli·bdSCd climate 'iCfll'''< the applicatton or this \'erS1011 (O \1!}\ (i n:ty b,·
appropmnc.
The kmrth lirnitatmn oi the model used in tlll:-> h that It dues not Uli.:ludc the pnH .... ;ss ot'
dilf n.:tn:aL \Vbik mduding a stochastic rockfall algorithm m SIBERIA wuuld r!l•! be dt
calibrating such a modd would be d!fficuh wnhout better quamification pf th.: a .. :wal !\!\ll:csseo;
Data !nnitation issw:s related to modclmg difY retreat an: dtscusscd hdmv.
4.2 Data Limitations
ln some cases, uncc11amtit:s were introdun:d bccmsc of the lack of adequate data for modd
puramch.:rizalion. Areas of particular ccmcem mdudc !be characteri;:arion or rhl' hydraul~~: and
crPslcmal properties of the proposed coveL lhc role 1Jr climate variability and c:;tn:mc cYcnts in
cover pcrlim11ancc. and the impact of Y~lrit)US ongoing gcumorpluc pmc\;:sscs un ~.-·over
pcrf(mnancc ;n MDA G
'flK' matcnal propt:nies of the cPvcr and hedwck are' critical daw for determining the prcdll~h.·d
pcrformaHce of the cover in relation to both cros!nn proccss~s aml mliltrat1on (Newman and
SchoflckL 2005 ). A critical paramev.:r for both processes is saturated hydraulic C(mducti\itv. Tlk·
SIBERIA ::mal:.·sis \vas pcrfonncd before the results or hydraulil· condw:tn ity measurements
pcrll.mT\cd on s:nnpks of thL~ propost·d 1..'0H'r material werL' in·nilnbk. ln th~: nbsem:c \11' :1
!11L':1sured value. Nc\\'man and Schofield 12D05l c~lmtatcd a saturated hydraulie comlucti\ or 0 fl3Q mm'hr ( J .3 ' lO-J in/hr) fin· the propoc.;cd co\'cr material This value ts almost 30(ltimcs
kss than the \ ulm: or ! I mm'hr {4.3 l 0 1 in.ihr) used in ISR q to compute runofl rnr the 2- and
5-war events thcd in S!Bl:]{J/\
The hydraulic <.:onducii\'t1 y values used in the ISR9 moddmg \H;re taken from literature values
(Nyhan ct aL. !99~; Channan and Murphy, I ·~for actual :il)ils with the same tcxnm: ( .. the
same propurtwns uf sand. silt and day) as that t\Jr the pmposcd cover. 'IlK' Newman and
Schutkld t 2005) mJiltmtion cllculations us~:d c,;timau:d hydraulic conductivities for a 6 pl·rccm
bcnhmite tuff rnixtun:. 'These cstimatcs \\ere based on n linear regression fit bet'>\ t:cn the
measured hydraulic conductivity of pure cmslhxl tufT and the va!uc n:pnrlcd m Nyhan ct a!
'· !997 l fur :1 1 n percent bentonite: tuff mixture. Both sels uf values have J imit:uh,ns.
unc;.;J1:ll
s:.scn li!emlt s, llllc:..: ul ~.·rrnr m th;,; suc(;Jc.: lTP.'i\Utl m'. Il!,:. l J Ilk' :tctua! \ ahk·s an.· [u\\ ..:·r than tll\.' \·alLII.'" Sl
~ub'lcqtll.:n! ;:wsinn. willlx lugrk·r than .h mcnt m:tt<.::rial hav..: been submilh:d l\1r ;umlv::;;s: tilL' n:sulh uf th1::;
Rami:dl simulatn; t.:\Jli..Ttmcnts earrtl·d ow Ptl kS! at a hillshlpl' t mclu.Jtn!,: m l!th.'S) \\\lUld !J~_:Jp !O llll' lllilhriltl!JlL Ct\lS!PlL Hl
cllantc!l:rist!cs ,,f S!!Jllific:mtl;,
lTusion a;;su~·wtcd wnh
\\ is nit
m the pi.'ri\wmmK'l' <t:isc:,:.!lh:llt
data about 1hc amnunt ui and widl: range r:nn!idl events l'Xpcc!cd under dml<tll'
to running smr RL\ \\ u climah.' C'\t'fll'S ratltt'l than {t srcady-sLnc bmlscapc-furming event The dc\·dopm;:m a :::.cr putt:nli:d futwT dnn:w.: :;c·ncs ;o us~·d
as mput to the· llL'\\' SIBERIA would help In tmccn;tintv rdatd !o dtmat<.· ilHd
prondc a hcn:.:r umkrstandmg of thc unccnamt: ass(lClaled \VJtl!
('vents.
Currently. ll 1:> rt<l! which of g~.·nnlmv!nc pn.K,::-s.::; at \11):\ (J pu.,;c the lP nfth..: waste umts. :\!though wugli .:stanarr.:-, ;;x.Jsl
Cut rluvi;tl :md w1
dndupmcnt cltff rcln.:a! r~ltcs rcqu1rcs 11L:aningful :,vt pf (ktc:·minc till.'
mass W<htmg (block l~d
;lhtlU! the cnlSlllll r:tk':-i .. \
•••••••••••••• ·---~'"""~'-m~~~A•~'"'"'" ~
"
mcnt-
ptOCC''·Sl~S. inclilddl',!
lll' If' t;_,
4.3 Comparison of SIBERIA Results to Field-Collected Data
ln '>pile ol' "(ltll\:<..'S ~,r cn\lr :md un..:cTt;unt: m the pan:mlch:ruat~>m <.lt the rnod.:l and
mPdL·I ~tw,·tmc, a l:• (>f annu:d : .. ~:dmlL'llt !h:ld h\ S!B!·HIA and tll:1t
that SlB!:RIA pcr!(lmtcd \\,;IL Tal>k 5 shows
\;II tk'.'i dcri h'd rrnm th. .. ·sc sites range !'rom [J.2 h) l l ifl:t HlOX(} t\1 () -+5 La c) pt.T
i~.~mmJg: <..'\L:llL thh JS <..:!p-.,c H• th~.· range of \:dth.:;-.. ,l(U . ..t \(' .>.:: l ·ha Hl!(> l\1 !.~ 1 :tv\
per C\ em
;;alu-.·s nmld
!hat the value:; den\ l'd
tl!i..' n:btiv,·ly sh,1n
Rita E:.pL·rirncntal \\ :ll<.'rslh.:d which included SC\'L'ral
T~1blc 5
on!~> )c{\t<.. ut'data
en \:.;wn<al C\ ~.·nts.
Estimated Sediment 'Vidd for Mesita dd Stu~: Sites thun Evt.mts with 2- and 5-Y t.•ar
Return Periods "
Return Period Runoff Volumes b (m3)
Mean Sediment
Concentration !mgJL)
Sediment Yield c
(T/ha)
Observation Drainage Site Area (m2)
TA-E·1 Runoff P!ots :l3E+01
Smai:' catchments TA-54
r"''"'"')~ :::.: .. ' 4 1E+Q3
;::?'1~ -:..LI 1 7E+04
E247 5 OE+04
2-Year Event
3.0E·01
52E•01
2.1E+02
3.2E+02
5-Year Event
8.3E+W
2.3E+03
2-Year Event
5.2E-01
27EA1i
5-Year Event
wflnrPrvLr;u iht~ 1near C!)l1Ccntrattor fro.m observed t:y· thr: calculated :uncf. ~olume These f"!&lds ~'::om pare
SiBERIA for the annual mnc7:iCiiiDe-romw;a event, as snown in Tabte 3
5.0 References
c :Hl'\. J \\ dlld Cok. < r .• .::no:::. 1 ! ',ac~ .'>·,·r. Ll"' .•\bm~.~ ...
.s·, u!1 /i;,·;r ll u!,·.;. :-;.n!ncv
Crt,wdL K.L ('J W!l...,un. and L..l. Lalh:, 2(Hi4. "( ''ilSlrainm~,:
, ' illlli '
F\olntwn \h>(k·l w !Uilll Y~.:ar~ ol Lrnsiun a! .·\mLTiGHl I mon l:d! \1
at :.1 ;\ksa·l <liJ \\ <hk
I; l kL>.:mth.·r. '-.::n l!." i (. 1 1 • .;.:::.
Da\.\1S.t.K. and C.D. f'cdcr:<JL 20115. t n11r
.-il'c\1 '..f .. \lil{CI'i,;/ /
· /.,Jr!ht'/1 ( ·(!\'c'f'
I rr -.; i • l
! h:im;-;ath . .'\./.L WJ:. Didric!L Ni3hivtnni. and R.C. linkd. 191l7. "Th~· S<nl Pn•dudtttn J· um:uon Lqmlibritm1 . ., .\aw,"L·. \. 3 ~:\. pp. 31• I.
Kin:!mc:r. J \\., RJ HnkcL ( .S Riebe. LU:. Crangl'L JJ .. l. bvton . .I.Cr. K \kgahan. 2001. "\•lmmtain Eroswn P\Cr 10 ;n. lU k.y and !0 nLy. Tun;;·
:\mcnc:L
Laflcn. l LJ l:t!K\ and (i.R. h!:>tCT. l tl•J L "\\ EPP· A. \('\\ {JC!ll~:·auon Predtc!wnT ."JofSuil~md\\~ncrC\•ns..:nati.HL \'ol -til. No. l.pp. -;4 .. ,:--:,
L.<m~.'. L.L \UL 1\. L.R, ~md
buS lUll iHld s .. :diln.:m y !dd at th..: Jl d Llnpc l!l t
.\U<. Ki,J\\r.:!L ::oOJ . .. :\ Sinmbt!tm ~"· ('hapli.'1 ?\ t rr-. 20 l 2~ 7) n1
R. S. . W \\ .JIL cds. L
\\ J, V<Ji
K luw(·t
Larll'. L J .. RunP!l Volumes [~xP::;i,m Pn:diction in Support Land:-.;;-;q1c L !Pil \ DA (L lm~"nm No, 3. i\h:l!HllU ;..;pp.
\..( li\A ( \:ni. & .\tmusphcn;;-'-\.T\ i.'L 'hdSL'. n \\ S.! H 1aa. f:'l 1\ {
\.;_'\\lll;HL HJ) ~md l ( i. 200:'. ( i1 oun,h\\tt. r l\lfhL ,n ,rr Los .·!lumns \'
! -'"' :\bntt'> '\;ttJrllo:ll Lahura11xy Rq>ort LA-l. :J\. o:;. ""fl 1l-l. S~.:pktnlK·r
' J.\\ (,J I C.F \lartin, J.l \bnmo. ·r (I. SchotkkL ! "Field
Stuch~> ,)f Lngllh:lTcd Closure Lm\ Lncl Radioar:tnc \Vash: Ltndi"ill.-. at thr· lii!rT!Idtiona! C
Var·\·ing m Slope li)r Scmmnd Rr.•gimh ... I
Pr.c"is. \\' .. S Tcukolsky. \\'. V cHr:riing. and B. Flannery. ! tFlh. Vwuenr n!
(. 2nd eeL c·amhnd,!!c Unin:r~·dtv pp. 4:\1 ··· 455.
<;,1mth. R.L. Cim,drich. llC, \\r1olhiscL D.A.and Lnknch. (
:1 kincmat1c runoff erosion model." in CompWrT ;\/rJd,·ls
Oil
V.P.t ~.:J l. \\;Her Rr:sotHYi.~S Pubhcalions. llighlamls R:mch. Coh1rado. pp. 697 132.
.!
. \' o!
in C
Smgh.
Stunc. LL. L.J L:me. and F.D. Slmky. 1 'N2. "'[nfi!tmtirHJ and RtmPIT Simulation on a Plmw:·
7 r,m.,uctirn:., American u{j17rn \ oL pp. l6l
USDA. 2002. lliffslope Erosion Model. Enginccn:d lnl~m11ation Syskms for Natm~tl 1\.esnurc~.:s.
t 1SDA-:\ RS Southwest \Vat~:rshed R-:·scan:h Center. TucMl!t. AZ.
hup: i, ctsnr tucscm.ars.ag.gov hi l!slopccmsinnm.Klc[ ·.
Willgoosl..'. Ci.R. and S. Riley. ! 998_ ''The Long Term Stability of Fngmccrcd Landfonns of thl'
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